Re: [PATCH 1/2] USB gadget: video class function driver

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Laurent Pinchart wrote:
> Hi Greg,
> 
> On Monday 03 May 2010 19:15:48 Greg KH wrote:
>> On Mon, May 03, 2010 at 02:29:57PM +0200, Laurent Pinchart wrote:
>>> On Monday 03 May 2010 13:14:11 Viral Mehta wrote:
>>>> Hi,
>>>>
>>>>> This USB video class function driver implements a video capture device
>>>> >from the host's point of view. It creates a V4L2 output device on the
>>>>> gadget's side to transfer data from a userspace application over USB.
>>>>>
>>>>> The UVC-specific descriptors are passed by the gadget driver to the
>>>>> UVC function driver, making them completely configurable without any
>>>>> modification to the function's driver code.
>>>> I wanted to test this code. I git cloned[1] tree. It has
>>>> v4l2-event.[c,h] and so I assume that now this tree has support for
>>>> v4l2 event code.
>>>>
>>>> But, while compilation, I am getting this error.
>>>> [root@viral linux-next]# make uImage > /dev/null && make modules
>>>>
>>>>   CHK     include/linux/version.h
>>>>   CHK     include/generated/utsrelease.h
>>>>
>>>> make[1]: `include/generated/mach-types.h' is up to date.
>>>>
>>>>   CALL    scripts/checksyscalls.sh
>>>>   Building modules, stage 2.
>>>>   MODPOST 5 modules
>>>>
>>>> ERROR: "v4l2_event_dequeue" [drivers/usb/gadget/g_webcam.ko] undefined!
>>>> ERROR: "v4l2_event_init" [drivers/usb/gadget/g_webcam.ko] undefined!
>>>> make[1]: *** [__modpost] Error 1
>>>> make: *** [modules] Error 2
>>>>
>>>> And by looking at the code, those symbols are not exported and thus the
>>>> error is obvious. Can you please point me out where to take v4l2-event
>>>> code? I tried to look for on linuxtv.org but was not able to locate the
>>>> right code.
>>>>
>>>> [1]git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-next.git
>>> There's a patch pending on the linux-media list to export those two
>>> functions. It has been acked by Sakari (the author of the V4L2 events
>>> patch set), but not committed by Mauro to his linux-next yet. That
>>> should be a matter of days.
>> Do you have a pointer to that patch?  I'll take it into my usb tree for
>> now, to keep things building, and let Mauro send it to Linus for
>> merging.
> 
> Sure
> 
> https://patchwork.kernel.org/patch/96373/
> 
> But please note it requires the V4L2 events patch set from Mauro's linux-next 
> tree.

Btw, this patch is already on my linux-next tree.

-- 

Cheers,
Mauro